J

John Vastola

Thank you for reading, and for your very kind words! I agree that these limitations are not cause for pessimism---it's amazing that we can understand so much about the universe, given all these obstacles in our way. The next best thing to knowing everything really isn't so bad.

Thanks for reading! Assuming Laplace's demon is part of the universe, it is subject to all the same physical laws we are, e.g. it cannot communicate information faster than the speed of light, it can only measure observables (and not things like wave function values), it has finite memory and computational speed, and so on.

Of course, there is no way to verify my assumptions regarding Laplace's demon, because Laplace's demon is not real; it's just a helpful device for thinking about what is (in principle) possible. But on the other hand, I think it's hard to reasonably argue that a being part of the universe could violate some of the restrictions I mentioned (e.g. communicating faster than light speed, measuring things that aren't observable, having infinite memory and computational speed). Laplace's demon isn't a theory so much as a tool that helps us think about the consequences of our existing theories.

Thanks for reading, and for the compliments. Interesting point, I'll have to read your essay to learn more.

Thank you for reading, and thank you for your very thoughtful comments. It's been a great pleasure, as part of this essay contest, to throw out some ideas and see people really engage with them (and vice versa).

I'm very sympathetic to your point about my 'we focus on understanding the understandable/easy problems' comment. I think that, although many non-scientists may disagree, it's somehow easier to come up with and understand the standard model of particle physics than it is to reliably understand people (or live a good life, or build a just society, or any of a number of important problems). Lots of real life problems are 'messy', while problems in physics/chemistry/biology/math/similar subjects can often be formulated in 'clean', abstracted, and well-posed forms. And for these messy problems, it's harder to know whether you're 'right', or you're just using arguments and/or data to fool yourself.

In spite of this, I will stick with the (admittedly strong) claim that we do have a working framework for understanding literally everything---although 'working' may be the operative word. Without a convincing alternative, people are trying to use science-like approaches to understand pretty much everything, from how human societies should be organized, to how to live a good life, to how to cook tasty food. I can't think of anything that isn't amenable to some combination of doing experiments, modeling, and pure thought/computation. Many of these endeavors outside of the 'easy' stuff (e.g. physics, chemistry, biology) are still young, like you say, but I'm optimistic that they will be fairly successful. I concede that my view here reeks of scientism, but I'm okay with that.

You're right that I was a little imprecise with my statement regarding human behavior being random. I've heard of the same 'ask a person to generate a random number' experiments too, and I find them very fascinating. It's funny that we think 1 is a less random number than 6 (if asked to give a number between 1 and 10), but I admit to making the same mistake myself sometimes. It's true that lots of human behavior is predictable, which is one of the empirical facts that allows us to live a relatively stable life without going crazy, but I will maintain that enough of it isn't for my statement to be reasonable. You can be relatively confident your friend won't strip naked and start flinging poo, but never completely confident (psychotic breaks can and do happen, for example)---and that's the point I was trying to make, albeit ineloquently.

Lastly, I agree that the truth/verifiability relationship is difficult, and think you make some excellent points. I do not claim to know the answer or to be able to resolve these issues, but I do think it's fun and productive to bring them up and discuss them.

Thank you again for the comments (and kudos on your thoughtful essay)! The intellectual back and forth is something I treasure.

Very nice essay! Clearly written and interestingly argued. Aesthetically the prettiest-looking essay I've seen. I like the use of blue for various headings/citations, and the figures you produced are all very beautiful and clear.

The point about Wolfram's Rule 110 cellular automaton was strikingly mind-boggling. I can't even object on the grounds that there is some infinity-related trick being used, because the set of all sequences of conscious thoughts (given finitely many brain states and finite human lifetimes) is finite...

I agree that science is all about relations. The idea of a particle's mass, for example, is only meaningful insofar as it helps us predict how a particle will behave when interacting with other particles. But on the other hand, this makes me worried when it comes to consciousness. I feel like the hard problem of consciousness is deliberately posed to exclude all scientific investigation (experimental, modeling, etc)---like you said, if you can measure it, it's not part of the 'hard' problem anymore.

Maybe I did not read carefully enough, but I am not sure I understand the consequences of your argument. How can the collection of all true propositions about the world, and the collection of facts about sentient experience, be equal? Does that mean the world may be one big collective dream?

John

First of all, great work! It's really impressive that you entered this essay contest, and must have taken a lot of time to write your ideas up. I certainly don't think I could have produced something like this when I was in high school. Best of luck in the college admissions process, I think you'll do quite well!

Second of all, it's true that there are a lot of mysteries in modern astrophysics---the strange rotation curves of some galaxies being one such mystery. In many cases, some of the most common explanations (dark matter in that case) have some unsatisfying aspects. Dark matter has never been directly detected, for example. So it's great to be skeptical, and to imagine and investigate alternatives (e.g. modified gravity is one alternative to dark matter).

Moreover, if you can show that an alternative theory produces both qualitatively and quantitatively true predictions (quantitative is important---people will demand the numbers match up!), generally speaking the scientific community will be happy to take up your idea with open arms. The scientists I know don't falsify data. If aspects of relativity (which has been tested pretty thoroughly, e.g. time dilation in particle lifetimes) are rigorously shown to not be true, scientists will accept it if your proof is convincing.

On the other hand, while it's tempting to throw up your arms and call lots of scientists dummies that don't understand that their favorite theory is clearly wrong (I want to do that quite often, myself), the reality is usually more complicated than that. And there's a lot of work out there you have to familiarize yourself with to be sure. Some of your claims (e.g. on pg. 4, you claim the sun may have a high abundance of heavy elements) have been well studied. People use the spectrum (light at various wavelengths) of stars like the sun to determine the abundance of various elements. According to empirical results from such spectroscopic studies, the sun is mostly hydrogen and helium.

Also, keep in mind that plenty of other scientists have had a hard time accepting counterintuitive theories like relativity. That's why people have thought them over so much, and tested so many consequences of them. So far it turns out to be mostly right in its regime of applicability, but no one will be sad if Einstein turns out to be wrong---we just want to know what the truth is about the universe!

Lastly, keep asking questions, working hard, and staying curious. It may be that you're right! But convincing people, and yourself, is a much harder task that requires lots of evidence and careful thinking. And remember, at the end of the day, that your task is to find the truth, not to confirm that your favorite theory is true. I am reminded of a great quote by Feynman:

"The first principle is that you must not fool yourself--and you are the easiest person to fool. So you have to be very careful about that. After you've not fooled yourself, it's easy not to fool other scientists. You just have to be honest in a conventional way after that."

John

Neat essay. I never thought about the fact that a quantum random number generator is not subject to RNG manipulation---but in hindsight it seems perfectly obvious! I also liked hearing about the early history of computing. It seems that giants like von Neumann truly did study everything under the sun.

One question. I am sympathetic to the view that quantum mechanics involves true randomness, i.e. that there is not some underlying deterministic theory controlling the probabilities we observe (and it seems you are sympathetic to this view as well). Of course, some people think these deterministic theories (e.g. Bohmian mechanics) are plausible. Do you think studying real quantum number generators (and whether they are 'truly' random) will help shed light on which interpretation is most reasonable? Or do you think such a question is beyond experiment, since the predictions of these interpretations usually all match? I'm not sure what to think on this topic myself.

John

Wow! Most of the essays I've seen here (including mine) draw some broad links between uncertainty in its various forms and undecidability/uncomputability, but yours is the first I've seen that draws a convincing direct link. Very interesting central idea about the relationship between quantum measurement and the halting problem. I like also your point about how the distinction between 'system' and 'measuring device' is artificial, and really just for our own convenience.

Is there some history of related ideas? In particular, do there exist models where people try to describe (ideally in some level of microscopic detail) the interaction between a 'system' and 'measuring device' from both directions: by treating the 'measuring device' as doing the measurement, and by treating the 'system' as doing the measurement? This is the first time I've heard about this, and it seems like an important thing to think about in trying to understand the measurement problem.

John

Glad to see a shout-out of the Koopman-von-Neumann formulation of classical mechanics. It is endlessly fascinating to me that the same (empirically successful) theory can be mathematically described in so many different-looking ways.

Interesting to hear about the work of people like Aharonov taking a closer look at what 'measurement' really means. It makes a lot of sense to me that there are subclasses of measurements like 'weak measurements'. Maybe this is part of the key to the puzzle.

Maybe we should indeed be open to using different number fields in physics. After all, all measurement outcomes are rational numbers, and in that sense the real numbers are only a kind of idealization. Perhaps the use of p-adic numbers (or something else) should be investigated more closely.

Finally, I am very sympathetic to the idea that the fundamental laws (as we know them) are emergent from some different description. One thing that makes this hard to probe, though, is that there are probably many underlying models from which the Standard Model or something like it can 'emerge'. Also, if we find a deeper description, does that emerge from something else? Is it emergence all the way down? Thank you for the well-written essay!

John

Interesting essay. I see what you're getting at with your point about the paradigm for physics (and maybe science in general) as a world in which one thing's behavior is entirely determined by external influences. In a slogan, we might say that intrinsic properties are meaningless; only properties relevant to interactions matter.

But on the other hand, what should be our conception of science, if not something like that? Maybe I just need to open my mind up, but it's hard for me to conceive of another (equally successful) way of looking at physics. But perhaps you're right that something new is required to understand things like consciousness, which in large part have eluded us so far.

John

Thanks for reading! Interesting, I've never heard of Von Weizsäcker (I don't know much about philosophy, to be honest). I like your essay, but I am still a bit confused about how we can know whether a given theory is semantically closed.

You discuss quite a lot of topics in your essay! One thing I wonder, based on what you wrote: how can we know when we have a semantically closed theory?

John

Thanks for reading! Yes, your essay was very interesting.

Interesting essay. One reason I think theoretical physicists tend not to like cell automata-like models is that they are hard to extract insight from. Even if a wizard gave us a cell automata model and told us it was the Theory of Everything, we would still probably like to come up with phenomenological descriptions of it that are easier to understand. Having the rules for such a model doesn't tell us why the consequences are what they are, e.g. why there appear to be four forces and why these rules cause atoms and galaxies to form. For a theory that we don't a priori know is right, these automata theories are also hard to test experimentally.

The thermodynamic arrow of time is, in some sense, pretty much understood. It doesn't have anything to do with wave/particle duality, since it happens in the classical mechanics to classical statistical mechanics transition also. It's an emergent consequence of having lots of chaotically moving particles. Formally, you get time irreversibility when you take the particle number N to infinity, a singular limit. There's a good chapter discussing all this in Chibbaro et al's "Reductionism, emergence, and levels of reality".

Not sure I understand your positions on presentism and free will. Maybe I did not read carefully enough.

John

Thank you for reading, and for the kind comments! That's an interesting idea. What do you mean by saying that the demon/its model/the person should be outside the original fractal? To me, it's important to imagine that all of them are a part of the universe, as we are. Given your idea about a fractal-like universe, what can a demon inside the fractal know?

Very interesting idea! I liked how you proposed an intuitive explanation for why particles (Qs, here) attract and repel. I also like that you propose an experimental test for your claim of absolute space. The idea that the known particles and other things are all emergent consequences from some simple rules or objects (like your Qs) is one I'm very sympathetic to, and there are many current ideas that are similar in spirit. For example, it's fashionable to imagine gravity and perhaps even spacetime as emerging from some simpler objects, like quantum bits.

Still, with a tremendous claim, you need to put quite a bit more work in to convince other people. In particular, you need to be able to calculate things and show that your theory gives the right answer. For example, how would you calculate the anomalous magnetic moment of the electron? You say:

"Decisively, as the Change Hypothesis can use exactly the same maths as QED, it can also be used to calculate exactly the same things and can immediately be used to explain most of physics!"

But if the calculation is the same as the QED one, why use your theory? You should show that it predicts (for some measurable quantity) an observable difference.

The math of QED (as you may know) is somewhat tougher than Feynman lets on in that book, which is great for intuitive understanding but not so great for learning real QED. If you haven't yet learned QED, I'd look at these two:

(Beginner level) Klauber's Student Friendly Quantum Field Theory

(More advanced) Schwartz's Quantum Field Theory and the Standard Model

Also, not sure what you mean by this here: "This means that light, for example, can have an amplitude to go faster or slower than the conventional speed c, which is also the case in QED"

John

Thanks for reading! Great question. My inclination is to believe that it would take a computer as big as the universe to effectively simulate the universe in complete detail---as you said, the universe should 'know' everything about itself! But I don't know how much power a universe-sized demon would lose for each atom you take away. You could say it loses a 'small' amount, but how do you define small here? What's the critical number of atoms or particles you have to take away in order for it to be effectively incapacitated (like a demonic ship of Theseus)? Hard to say.

Although I didn't specify in the essay, I think in any case that it's more interesting to speculate about a demon whose size is small compared to the universe overall. Partly because it's hard to imagine such a demon doing experiments, thinking (is its ability to think hampered somehow by the finite speed of light?), and communicating with us. And partly because I was thinking about the demon as an idealization of our own struggle to understand the universe.

Jim, I commented on and rated yours on May 2nd.

Very intriguing essay! The central idea, (which I understood to be) that one might be able to get around Bell's theorem by having aspects of the underlying deterministic theory be uncomputable in a certain precise sense, is very clever. It's much better than a philosophical monstrosity like superdeterminism, too...Still, I admit I did not fully understand all of the technical details. Maybe I will reread it again.

Here's a philosophical question, though. There's how the universe 'really is', and there's the collection of things we can ever know about it; these sets are almost certainly not equivalent. If there is some sort of deterministic theory that underlies quantum mechanics, but it has the property that it 'looks' probabilistic to us because of uncomputability etc, why should we prefer the deterministic theory? I guess it's possible that ideas like this could help with unification, but it seems to me necessary that the proposed unification would suggest some experiment that would distinguish between the different possibilities in order for that unification to be useful.

More generally, how can we ever know the 'true' behavior of quantum mechanics, given all these clever alternatives?

John

Thank you for the very kind words, Flavio!

I agree that information being "inaccessible in principle" is a useful concept, and that one must be mindful that determinism vs indeterminism may not be black and white. However the universe really 'is', there are ample restrictions on what we can know about it...whether it's better to describe the universe as it 'is' or in terms of what we can ever possibly know about it is an interesting question. I don't pretend to know the answer!

Great point about classical vs quantum mechanics. I really enjoyed discussion along these lines in your essay, and never thought before about the strong metaphysical assumption that observables really 'are' determined to infinite precision in classical mechanics, though our ability to measure them is restricted. Perhaps they are not determined to infinite precision. It's hard to imagine a way to tell the difference. Still, which formulation is more useful in practice is amenable to debate/discussion, I think.

Thanks for the paper link, I'll take a look at it.